Rollaway cover for generator auxiliaries



July 22, 1947. I c, c. STERRETT 2,424,340

ROLLAWAY COVER--FOR GENERATOR AUXILIARIES Filed Sept. 7, 1945 INVENTOR' ATTORNEY Patented July 22, 1947 UNITED STATES PATENT OFFICE ROLLAWAY COVER FOR GENERATOR AUXILIARIES Application September 7, 1945, Serial No. 614,946

2 Claims.

My invention relates to a new-type, rollaway exciter-cover, for covering the collectors, mainexciter and pilot exciter of a large synchronous generator, motor or condenser, such as may be installed in a central station or a substation of a large electrical transmission system.

The general object of my invention is to provide a new type of exciter-cover which provides more ready access to the collector, commutator or commutators, and other parts which require maintenance.

Another object is to provide a rollaway exciter-cover which leaves the floor-line substantially clean and smooth, when the exciter-cover is removed, and which aids appreciably in the servicing of the exciter and associated accessories, because of the absence of sharp obstructions which would interfere with the workmans arms and shoulders,

A more specific object of my invention is to provide a rollaway exciter-cover having retractable wheels which may be readily lowered for the purpose of rolling the cover away in an axial direction, to expose the excitersand, other accessories.

A still further object of my invention is to provide an axially removable cover for a compartmented space surrounding the shaft-end of a horizontal-shaft machine, the machine having a plurality of stepped-diameter bulkheads, for providing a plurality of axially displaced compartments surrounding the shaft, and the cover having corresponding inwardly depending, axially spaced ribs, having packing-means for engaging said stepped-diameter bulkheads, respectively.

With the foregoing and other objects in view, my invention consists in the apparatus, structures, combinations and parts hereinafter described and claimed, and illustrated in the accompanying drawing, wherein Figure l is a perspective view of the exciterend of a large hydrogen-cooled, synchronous generator, with parts broken away to illustrate my new rollaway exciter-cover, and

Figure 2 is a longitudinal sectional view of the cover, after it has been rolled axially away from the exciter-end of the machine.

In Fig. 1, my invention is shown as being applied to a large synchronous generator, which might, in general, be any dynamo-electric machine. The generator proper comprises a main stator-member which is enclosed in a hydrogenfilled housing 3, the lower portion of which extends down below the floor-lever 4, into a pit 5 which is provided in the foundation. The generator has a horizontal shaft 6 which extends out through an opening "I in the end wall or bulkhead 8 of a stator-endbell 9 of the main housing 3, the level of the shaft being somewhat above the floor-level 4. The shaft is supported on a bearing H which is shown as being disposed in a gas-tight manner within the opening I in the endbell 9. The shaft-end 6 carries the slip-rings or current-collector l2 of the main machine, and terminates in a shaft-coupling l3. Suitable stationarily supported brush-rigging l4 cooperates with the collector l2.

Coupled to the shaft-coupling I3 is the shaft !5 of a main exciter l6, and usually also, beyond the main exciter, at the end of the shaft 15 furthest away from the main machine, a pilot exciter H. The exciter-shaft l5 may be regarded, in effect, as a part of the shaft-end 6 which extends out of the main machine.

The exciter-shaft carries the following equipment, starting at the coupling I3: First an exciter-bearing 2|, then a main-exciter commutator 22, then a main-exciter armature 23, then another exciter-bearing 24, then a pilot-exciter armature 25, and finally a pilot-exciter commutator 26.

The stationary parts of this exciter-equipment include suitable brush-rigging 21 and 28, for the main and pilot-exciter commutators 22 and 26, respectively, and the main and pilot-exciter frames 29 and 30, respectively.

It is usually desirable to provide the shaft-end equipment with a plurality of bulkheads 3|, 32 and 33, in addition to the bulkhead 8 at the end of the main machine. These bulkheads are for the purpose of dividing this space into several axially displaced compartments, which permit of proper ventilating-circuits.

My present invention is characterized by having an exciter-ccver 35, or other shaft-end equipment-housing, which is removable, in an axial direction, away from the end of the machine. Notwithstanding this provision for the axial removal of the cover or housing 35, the previously utilized compartmentation is nevertheless preserved, in my invention, by causing the bulkheads 3l, 32 and 33 to have successively larger outer diameters, with the smallest bulkhead 3! at the pilot-exciter end, and by providing the cover 35 with a plurality of inwardly depending, axially spaced ribs 36, 31, 38 and 39, of correspondingly stepped inner diameters, for fitting. up against the mating bulkheads 3|, 32, 33 and 8, respectively, when the exciter-cover is moved into place on the machine. Preferably, the ribs 35, 37, 38 and 39 are provided with suitable rubber packing-means Al, or any equivalent packing-means for making a fairly tight contact With the several bulkheads.

The eXciter-cover 35, or other equipment-housing, is provided with side-members 42, and an end-member 43, which extend down substantially to floor-level, and which terminate in flanges or other packing-means 44 for making a fairly tight contact with the floor, when the housing is in place on the machine. In this manner, a fairly tight enclosure of the shaft-end equipment is provided.

The endwise or axial movement of the excitercover 35 is facilitated by providing the same with retractable Wheels 46, which are mounted on bellcrank-levers 41 disposed along the inner sides of the side-members 42 of the cover, near the bottom edge thereof. These bellcrank-levers 43 are simultaneously actuated, by a system of tie-rods 43 and a pivoted yoke 43, the top bight-portion 50 of the yoke carrying a handle-bar which extends out in front of the exciter-cover or housing 35, through the end-Wall 43 thereof. The handle-bar 5! can be pushed in, so as to retract the wheels 53, thus letting the exciter-cover or housing 35 down on the floor, or the handle-bar 5! may be pulled forward, after depressing the button 52 to release a spring-catch 53, so as to depress the wheels d6, thus elevating the excitercover or housing 35 a half-inch, or other suitable distance, above the floor-level 4. A counterbalancing spring 54 is preferably associated with the yoke 49 for slightly more than counterbalancing the weight of the exciter-cover or housing 35, so that the lowering and retraction of the wheels is facilitated, and so that the wheels will remain in their lowered position when the handlebar 51 is pulled out.

In operation, when the exciter-cover or housing 35 is in place, covering the shaft-end equipment of the machine, it makes a fairly tight contact, all around, both with the floor 4 and the endwall or bulkhead 8 of the main machine. At the same time, the several ribs 36, 37 and 38 of the cover make fairly tight contacts with the respective bulkheads 3!, 32 and 33 of the shaft-end equipment. When access is to be had to the shaftend equipment, the cover or housing 35 is rolled away in an axial direction, after first lowering the wheels 46 by manipulating the handle-bar 5|, thus leaving the entire space, surrounding the shaft-end equipment, substantially free of obstructions, affording the freest possible access to said equipment. At the same time, the floorlevel 4 is left substantially clean and smooth, with no obstruction other than small guide-rails 56 which may be provided for guiding the rollaway operation of the cover.

I claim as my invention:

1. A dynamo-electric machine having a main stator-member having an endbell, and a rotormember having a horizontally disposed rotatable shaft, said endbell comprising a bulkhead surrounding said shaft, and said shaft having a shaft-end extending through the endbell, said machine having shaft-end equipment associated with the extending end of the shaft, and an axially removable equipment-housing for said shaft-end equipment, means for mounting said main stator-member on a foundation, said foundation including a floor and a pit, and a portion of said main stator-member extending down below floor-level in said pit, said equipmenthousing having side-members and an end-member extending down substantially to floor-level, and wheel-mounting means for so mounting said equipment-housing that it is movable in an axial direction away from said stator-endbell, said wheel-mounting means comprising retractable wheels, and wheel-shifting means whereby said Wheels may be either retracted up into the housing or depressed so as to elevate the housing slightly from floor-level, said housing having packing-means for making fairly tight contacts with the floor and the endbell-bulkhead, respectivelyi when said housing is in place in covering relation to said shaft-end equipment.

2. A horizontal-shaft machine having a plurality of different equipments spaced axially from each other, said equipments including a plurality of axially spaced bulkheads for providing a plurality of axially spaced compartments, and a rollaway cover for a plurality of said equipments, said cover having side-members and an end-member extending down substantially to floor-level, said cover also having a plurality of inwardly depending axially spaced ribs having packing-means for engaging a plurality of said bulkheads, respectively, and wheel-mounting means for rolling said cover axially away from said equipments, said wheel-mounting means comprising retractable Wheels, and wheel-shifting means whereby said wheels may be either retracted up into the cover or depressed so as to elevate the cover slightly from the floor, the endmost rib of said cover having the smallest inner diameter, and successive axially spaced ribs having successively larger inner diameters, the corresponding bulkheads having progressively larger outer diameters, said cover also having packing-means for engaging the floor when the wheels are retracted, with the cover in place on the machine.

CHARLES C. STERRETT.

REFERENCES CITED UNITED STATES PATENTS Name Date Brown Apr. 28, 1931 Number 

